Hsueh C, Kuo T T
Department of Pathology, Chang Gung Children's Hospital, Kwei San, Tao Yuan Taiwan, Republic of China.
Arch Pathol Lab Med. 1998 Dec;122(12):1099-102.
The congenital occurrence of malignant rhabdoid tumor (MRT) is rare. Initial presentation of congenital MRT as a skin tumor is even more rare. We report 2 cases in which a cutaneous nodule appeared prior to the discovery of the primary tumor.
Histologic, ultrastructural, and immunohistochemical studies were performed on skin nodules from 2 neonates. Other congenital examples of MRT in the literature were reviewed.
Both neonates were male and both were fullterm. Skin nodules were noted at birth. The tumors were located on the right neck in case 1 and on the right back in case 2. The primary tumors were later found in the kidney and the right chest wall, respectively. The skin biopsy of the first case had been interpreted as undifferentiated sarcoma, and MRT was diagnosed after the renal tumor was examined. In the second case, a correct diagnosis was promptly made based on the skin biopsy owing to experience with the first case.
Congenital MRT is very uncommon and may present as a skin tumor at birth. Since MRT exhibits various histologic patterns, the diagnosis should be made by a complete pathologic study with proper clinical correlation. To our knowledge, the unique mode of manifestation in these 2 cases is described for the first time. We suggest that MRT should be considered when making the differential diagnosis in such a clinical setting.
先天性恶性横纹肌样瘤（MRT）的发生较为罕见。先天性MRT最初表现为皮肤肿瘤的情况更为罕见。我们报告2例在原发性肿瘤被发现之前出现皮肤结节的病例。
对2例新生儿的皮肤结节进行了组织学、超微结构和免疫组化研究。并对文献中其他先天性MRT的病例进行了回顾。
2例新生儿均为男性且均为足月儿。出生时即发现皮肤结节。第1例肿瘤位于右颈部，第2例位于右背部。原发性肿瘤后来分别在肾脏和右胸壁被发现。第1例的皮肤活检最初被诊断为未分化肉瘤，在肾脏肿瘤检查后确诊为MRT。第2例由于有第1例的经验，基于皮肤活检迅速做出了正确诊断。
先天性MRT非常罕见，可能在出生时表现为皮肤肿瘤。由于MRT表现出多种组织学模式，诊断应通过完整的病理研究并结合适当的临床情况来做出。据我们所知，这2例独特的表现模式是首次被描述。我们建议在这种临床情况下进行鉴别诊断时应考虑MRT。
